Write-once disc, recording apparatus thereto, and method of reducing access time thereto

ABSTRACT

A write-once disc, an apparatus for recording information thereon, and a method of reducing access time thereto the write-once disc including at least one record layer. The write-once disc also includes at least one update area in which updated predetermined information is recorded; and an access information area in which location information regarding the updated predetermined information, is recorded for a predetermined period. Accordingly, it is possible to reduce an access time for reading information updated in the write-once disc on which predetermined information is updated and recorded on a new position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 10/765,954filed Jan. 29, 2004, now pending, which claims the benefit of KoreanPatent Application Nos. 2003-12868 filed on Feb. 28, 2003, and2003-12952 filed on Mar. 3, 2003, in the Korean Intellectual PropertyOffice, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to recording information on and/orreproducing information from a write-once disc, and more particularly,to a write-once disc, an apparatus for recording information thereon,and a method of reducing access time thereto.

2. Description of the Related Art

Unlike a rewritable disc, it is impossible to rewrite data to a portionof a write-once disc where data has already been recorded. That is, oncethe data is recorded on the write-once disc, it is impossible to deletethe data and record new data thereon. Accordingly, a new portion of thewrite-once disc must be allotted to update the already recorded data.

In general, since only last updated information on a disc is available,a recording and/or reproducing apparatus first scans the disc to detectthe last updated information. The more information to be updated, thelonger the time required for scanning the disc to obtain recentinformation from the disc. In particular, this problem becomes moreserious for a write-once disc, since whenever information is updated,the updated information is recorded at different portions of an area ofthe write-once disc unlike a rewritable disc. If the size of the areawhere information is updated is reduced to lessen disc scanning time,desired information can be detected fast, but a number of times forupdating information is limited.

SUMMARY OF THE INVENTION

The present invention provides a write-once disc, and a method of andapparatus for recording information on the write-once disc in a datastructure such that a disc access time for reading updated informationis reduced.

According to an aspect of the present invention, there is provided awrite-once disc with at least one record layer, including at least oneupdate area in which updated predetermined information is recorded; andan access information area in which location information regardinginformation, which is last updated and recorded in the at least oneupdate area, is recorded for a predetermined period.

According to another aspect of the present invention, there is provideda write-once disc with at least one record layer, comprising a pluralityof update areas in which predetermined information is updated andsequentially recorded; and an access information area in which locationinformation regarding information, which is last updated and recorded inthe update areas, is recorded per predetermined period. Here, locationinformation regarding information last updated is recorded in at leastone of the update areas.

According to yet another aspect of the present invention, there isprovided a method of reducing an access time for accessing a write-oncedisc with at least one record layer, the method comprising sequentiallyrecording updated predetermined information in at least one update areawhich is present in at least one of a lead-in area, a data area, alead-out area, and an outer area; and recording location informationregarding information, which is last updated in the update area, in anaccess information area present in at least one of the lead-in area, thedata area, the lead-out area, and the outer area per predeterminedperiod.

According to still another aspect of the present invention, there isprovided a method of reducing access time for accessing a write-oncedisc with at least one record layer, the method comprising sequentiallyrecording updated predetermined information in a plurality of updateareas which are present in at least one of a lead-in area, a lead-outarea, and an outer area; recording location information regardinginformation, which is last updated in at least one of the update areas,in one of the update areas; and recording location information regardingthe information, which is last updated in one of the update areas, in anaccess information area present in at least one of the lead-in area, thelead-out area, and the outer area per predetermined period.

According to still another aspect of the present invention, there isprovided an apparatus for recording information on a write-once discwith at least one record layer, the apparatus comprising arecording/reading unit that records information on or reads data fromthe write-once disc; and a controller that controls therecording/reading unit to sequentially record updated predeterminedinformation in at least one update area of the write-once disc, andrecord location information regarding information, which is last updatedin the at least one update area, in an access information area of thewrite-once disc per predetermined period.

According to still another aspect of the present invention, there isprovided an apparatus for recording information on a write-once discwith at least one record layer, the apparatus comprising arecording/reading unit that records information on/or reads data fromthe write-once disc; and a controller that controls therecording/reading unit to sequentially record updated predeterminedinformation in a plurality of update areas of the write-once disc;record location information regarding information, last updated in oneof the update areas; and record location information regardinginformation last updated in the updated area in an access informationarea of the write-once disc per predetermined period.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a block diagram of a recording apparatus according to anembodiment of the present invention;

FIGS. 2A and 2B illustrate structures of a write-once disc according toembodiments of the present invention;

FIG. 3 illustrates a data structure of a write-once disc with an accessinformation area and an update area, according to an embodiment of thepresent invention;

FIG. 4 is a reference diagram illustrating recording of data on awrite-once disc, according to an embodiment of the present invention;

FIGS. 5A through 5D are reference diagrams respectively illustratinglocation information recorded in an access information area of awrite-once disc, according to embodiments of the present invention;

FIG. 6 illustrates a data structure of location information AA #iillustrated in FIGS. 4 and 5A through 5D;

FIG. 7 is a reference diagram illustrating recording of data on awrite-once disc, according to another embodiment of the presentinvention;

FIG. 8 illustrates a data structure of information A #i recorded in anupdate area A of FIG. 7;

FIG. 9 illustrates a data structure of a write-once disc according to anembodiment of the present invention; and

FIG. 10 illustrates detailed diagrams for explaining recording of datain a user data area and a spare area of a write-once disc, according toan embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to the like elementsthroughout. The embodiments are described below to explain the presentinvention by referring to the figures.

FIG. 1 is a block diagram of a recording apparatus according to anembodiment of the present invention. Referring to FIG. 1, the recordingapparatus includes a recording/reading unit 1, a controller 2, and amemory 3. The recording/reading unit 1 records data on a disc 100, whichis an information storage medium according to an embodiment of thepresent invention, and reads back the data from the disc 100 to verifythe accuracy of the recorded data. The controller 2 controls therecording/reading unit 1 to record data in a data structure according tothe present invention. More specifically, the controller 2 controls therecording/reading unit 1 to sequentially record updated information inat least one update area of the disc 100, and record locationinformation, which specifies a recording position of last updatedinformation in the update area, in an access information area of thedisc 100 for a predetermined period. In this embodiment, information isrecorded in the update area in recording units. The location informationis recorded in the access information area whenever a predeterminednumber of recording operations end or a predetermined number of logicalor physical recording blocks of the update area are filled with data.Alternatively, the location information is recorded when at least one ofa plurality of update areas is updated a predetermined number of timesor a number of times of updating information in the plurality of updateareas reaches a predetermined number. Further, if the disc 100 includesthe plurality of update areas, the controller 2 controls therecording/reading unit 1 to record location information, which specifiesa recording position of last updated information in at least one updatearea, in the access information area. For disc finalization, thecontroller 2 controls the recording/reading unit to record the locationinformation regarding information, which is last recorded in the updatearea, in the access information area.

Here, the recording operation is an operation determined according to auser's intention or a recording work to be performed. According to thisembodiment, a recording operation indicates a process in which the disc100 is loaded into the recording apparatus, data is recorded on the disc100, and the disc 100 is taken out from the recording apparatus. When auser presses the eject button (not shown) of the recording apparatus inorder to remove the disc 100 after recording of data, the controller 2expects the recording operation to be terminated.

In particular, the controller 2 tests recording conditions to adjust alaser power in the recording/reading unit 1, controls therecording/reading unit to record data based on the test result, andperforms disc defect management. More specifically, to adjust the laserpower, the controller 2 tests recording conditions in at least onelogical or physical block of a test area, where recording conditions aremeasured, in recording operation units. The test area is included in theupdate area of the disc 100. Accordingly, it is required to detect aposition of the test area where recording conditions will be tested nexttime. Data recorded for test is recorded and updated in the test area.Also, for disc defect management, the controller 2 uses averify-after-write method in which data is recorded on the disc 100 inpredetermined units of data and the accuracy of the recorded data isverified to detect if an area of the disc 100 has a defect. In otherwords, the controller 2 controls the recording/reading unit 1 to recorduser data on the disc 100 in units of recording operations and verifiesthe recorded user data to detect an area of the disc 100 in which adefect exists. Thereafter, the controller 2 creates informationindicating the position of the area with the defect and stores thecreated information in the memory 3. When the stored information reachesa predetermined amount, the controller 2 controls the recording/readingunit 1 to record the stored information as temporary defect informationin an update area, i.e., a temporary defect management area (TDMA), ofthe disc 100. Next, the controller 2 controls the recording/reading unit1 to further record temporary defect management information for managingthe temporary defect information in the TDMA. During each recordingoperation, data is recorded and verified at least once; in general, datais recorded and verified several times. Defect information obtainedusing the verify-after-write method is temporarily stored as temporarydefect information in the memory 3. When the recording operation ends,the controller 2 controls the recording/reading unit 1 to rewrite thetemporary defect information, which is stored in the memory 3, to adefect management area (DMA) of the disc 100.

When the recording of data is completed, i.e., additional data will notbe recorded on the disc 100 (the disc 100 needs to be finalized), andthe controller 2 controls the recording/reading unit 1 to rewrite thetemporary defect information and the temporary defect managementinformation, stored in the TDMA, to the DMA.

FIGS. 2A and 2B illustrate structures of the disc 100 of FIG. 1,according to embodiments of the present invention. FIG. 2A illustratesin detail a disc 100 having a single record layer L0 (single recordlayer disc). The disc 100 includes a lead-in area, a data area, and alead-out area. The lead-in area is located in an inner part of the disc100 and the lead-out area is located in an outer part of the disc 100.The data area is present between the lead-in area and the lead-out areaand divided into a user data area and a spare area. The user data areais an area where user data is recorded, and the spare area is areplacement area for the user data area having a defect, serving tocompensate for loss in the recording area due to the defect.

FIG. 2B illustrates a disc 100 having two record layers L0 and L1(double record layer disc). A lead-in area, a data area, and an outerarea are sequentially formed from the inner part of the first recordlayer L0 to its outer part. Also, an outer area, a data area, and alead-out area are sequentially formed from the outer part of the secondrecord layer L1 to its inner part. Unlike the single record layer discof FIG. 2A, the lead-out area is present in the inner part of the disc100 of FIG. 2B. That is, the disc 100 of FIG. 2B has an opposite trackpath (OTP) in which data is recorded starting from the lead-in area ofthe first record layer L0 toward its outer area and continuing from theouter area of the second record layer L1 to its lead-out area. The sparearea is allotted to each of the record layers L0 and L1.

In this embodiment, the spare areas are present between the lead-outarea and the user data area and between the user data area and the outerarea. However, if necessary, a portion of the user data area may be usedas another spare area, that is, more than one spare area may be presentbetween the lead-in area and the lead-out area.

FIG. 3 illustrates a data structure of the disc 100 of FIGS. 2A and 2B,in which an access information area and update areas are present in alead-out area or an outer area, according to an embodiment of thepresent invention. Referring to FIG. 3, if the disc 100 is a singlerecord layer disc, the access information area is present in at leastone of the lead-in area and the lead-out area. If the disc 100 is adouble record layer disc, the access information area is present in atleast one of the lead-in area, the lead-out area, and the outer area. Aplurality of the access information areas may be formed in separateareas or may be formed separately in the same area.

Further, when the disc 100 is a single record layer, at least one updatearea is present in at least one of the lead-in area and the lead-outarea. When the disc 100 is a double record layer, at least one updatearea is present in at least one of the lead-in area, the lead-out area,and the outer area. FIG. 3 illustrates two update areas A and B in whichinformation to be updated is respectively recorded. In this embodiment,predetermined information is updated and recorded in the update areas Aand B in recording operation units. A period for updating informationmay be changed depending on characteristics of information to berecorded or a user's desire. In the access information area, locationinformation regarding respective information that is last updated in theupdate areas A and B is recorded per predetermined period. In thisembodiment, the location information is recorded in a predeterminednumber of recording operation units or is recorded whenever apredetermined number of logical or physical blocks are filled withinformation. If necessary, only location information, which specifiesrecording locations of information updated in parts of a plurality ofupdate areas, may be recorded in the access information area.

For access time, a size of a block, which is a basic unit for errorcorrecting code (ECC), of the update area A is preferably small. Duringa write operation, location information regarding the location ofinformation last recorded in at least another update area is recordedwhenever information recorded in the update area A is recorded. When atotal number of recording operations are expected to be small accordingto characteristics of data to be recorded or a user environment, aperiod of updating the location information recorded in the accessinformation area is determined to be short. Otherwise, the period may bedetermined to be long. An instant of time when the location informationrecorded in the access information area is updated, may also bedifferently determined.

During a read operation, information for accessing information recordedin the updated areas is obtained by reading location information lastrecorded in the access information area while scanning the accessinformation area starting from a start thereof. For disc finalization,location information regarding information last recorded in therespective updated areas is recorded in the access information area.

In this embodiment, an update area is present in at least one of thelead-in area, the lead-out area, and the outer area. However, anotherupdate area may be further present in a user data area, if necessary. Inother words, predetermined information is updated and recorded in anupdate area, and a location of the update area is not limited.

FIG. 4 illustrates a method of recording information on the disc 100,according to an embodiment of the present invention. Referring to FIG.4, information is updated n times and sequentially recorded as A#1, A#2,. . . , A#n in an update area A, and information is updated n times andsequentially recorded as B#1, B#2, . . . , B#n in an update area B.Next, location information AA#1 regarding the information A#n lastupdated and recorded in the update area A and the information B#n lastupdated and recorded in the update area B is recorded in an accessinformation area. The location information AA#1 may specify physical orlogical addresses of the information A#n and B#n. Next, information isupdated n times and sequentially recorded as A#n+1, A#n+2, . . . , A#2 nin the update area A, and information is updated n times andsequentially recorded as B#n+1, B#n+2, . . . , B#2 n in the update areaB. Similarly, location information AA#2 is recorded in the accessinformation area. Alternatively, location information AA#i recorded inthe access information area may include only location informationregarding information last updated and recorded in the update area A orB.

Further, once information is updated n times and recorded in the updatearea A or B, location information may be recorded in the accessinformation area regardless of a number of updating information recordedin the other update area B or A. Therefore, when a number of times ofupdating the information recorded in the update areas A and B is n, thelocation information may be recorded in the access information area.

FIGS. 5A through 5D illustrate location information recorded in anaccess information area, according to embodiments of the presentinvention. Referring to FIG. 5A, the location information is repeatedlyrecorded in the access information area. More specifically, firstlocation information AA#1 is recorded at a start of the accessinformation area, so that physical or logical addresses increase. Next,a copy of the first location information AA#1 is recorded. Next, secondlocation information AA#2 is recorded, and then, a copy of the secondlocation information AA#2 is recorded. Recording the same informationtwice increases the reliability and robustness of information. Thenumber of times of recording the same information may be more than twiceand the same information may be recorded using an interleaving method.

Referring to FIG. 5B, as compared to FIG. 5A, location information isrepeatedly recorded in the access information area but the sequence ofrecording the location information is not the same. More specifically,first location information AA#1 is recorded starting from an end of theaccess information area, so that physical or logical addresses decrease.Next, a copy of the first location information AA#1 is recorded, andthen, second location information AA#2 is recorded. Next, a copy of thesecond location information AA#2 is recorded. Recording the sameinformation twice increases the reliability and robustness ofinformation. Similarly, the number of times of recording the sameinformation may be more than twice and the same information may berecorded using an interleaving method.

The access information area of FIG. 5C is physically or logicallydivided into two sub areas. In a first sub area, first locationinformation AA#1 and second location information AA#2 are sequentiallyrecorded, so that physical or logical addresses increase. In a secondsub area, a copy of the first location information AA#1 and a copy ofthe second location information AA#2 are sequentially recorded.Regarding a sequence of recording the information, the first locationinformation AA#1, the copy of the first location information AA#1, thesecond location information AA#2, and the copy of the second locationinformation AA#2 are sequentially recorded. In this embodiment, theoriginal information and a copy thereof are recorded in different areas,thereby increasing the reliability and robustness of information.Alternatively, the access information area may be divided into three oremore sub areas, and location information may be recorded at least threetimes.

As compared to FIG. 5C, the access information area of FIG. 5D isphysically or logically divided into two sub areas, but the sequence ofrecording location information is not the same. More specifically, firstlocation information AA#1 and second location information AA#2 aresequentially recorded in a first sub area, so that physical or logicaladdresses decrease. Also, a copy of the first location information AA#1and a copy of the second location information AA#2 are sequentiallyrecorded in a second sub area, so that physical or logical addressesdecrease. The sequence of recording the information is the same asillustrated in FIG. 5C. That is, the first location information AA#1,the copy of the first location information AA#1, the second locationinformation AA#2, and the copy of the second location information AA#2are sequentially recorded. The original information and a copy thereofare recorded in different areas, thereby increasing the reliability androbustness of information. Alternatively, the access information areamay be divided into three ore more sub areas, and location informationmay be recorded at least three times.

FIG. 6 illustrates a data structure of location information AA#i asshown in FIG. 4 and FIGS. 5A through 5D. Referring to FIG. 6, thelocation information AA#i contains an identifier, an access pointer toan update area A, and an access pointer to an update area B. The accesspointer to the update area A points to a recording position ofinformation last updated and recorded in the update area A. The accesspointer to the update area B points to a recording position ofinformation last updated and recorded in the update area B. Forinstance, an access pointer indicates a starting address of lastrecorded information.

FIG. 7 illustrates a method of recording information on the disc 100,according to another embodiment of the present invention. Referring toFIG. 7, as shown in FIG. 4, predetermined information is updated n timesand sequentially recorded as A#1, A#2, . . . , A#n in an update area A,and predetermined information is updated n times and sequentiallyrecorded as B#1, B#2, . . . , B#n in an update area B. Next, locationinformation AA#1 regarding information A#n last updated and recorded inthe update area A and information B#n last updated and recorded in theupdate area B is recorded in an access information area. The locationinformation AA#1 may specify physical or logical addresses of theinformation A#n and B#n. Next, predetermined information is updated ntimes and sequentially recorded as A#n+1, A#n+2, . . . , A#2 n in theupdate area A, and predetermined information is updated n times andsequentially recorded as B#n+1, B#n+2, . . . , B#2 n in the update areaB. Next, location information AA#2 regarding information A#2 n lastupdated and recorded in the update area A and information B#2 n lastupdated and recorded in the update area B is recorded in the accessinformation area. Alternatively, location information AA#i recorded inthe access information area may include only location informationregarding last updated information recorded in the update area A or B.

The information A#1, A#2, . . . , A#n+1, . . . , A#2 n further includelocation information specifying location of last updated informationrecorded in the update area B. For instance, the location informationincluded in the information A#n+1, which is recorded in the update areaA, points to a recording position of the corresponding information B#n+1recorded in the update area B. For this reason, whenever the update areaB is updated, the update area A must also be updated. For instance,sometimes the information A#1, A#2, . . . , A#n+1, . . . , A#2 n need tobe updated although there is no change therein, only because theinformation recorded in the update area B changes. In a worst-casescenario, when instants when updating a plurality of update areas aredifferent from one another, and a recording position of last updatedinformation is recorded in the update area A whenever informationrecorded in update areas other than the update area A is updated, a sizeof the update area A is required to be the same as or larger than a sumof sizes of the other update areas. To prevent such a problem, instantswhen updating the other update areas are preferably the same to minimizethe size of the update area A. Also, after recording updated informationin the other update areas, the information recorded in the update areaA, which is updated, and location information regarding at least oneinformation recorded in the other update areas are recorded in theupdate area A. Information is recorded in the update area A aftercompleting recording information in the other update areas, since apredetermined recording position of last updated information in theother update areas can be changed. When a position of recording lastupdated information in the update area B has been determined andlocation information regarding the last updated information is recordedin the update area A, if an ECC error occurs in the update area B afterrecording the last updated information in the update area B, a positionof the last updated information in the update area B may change.

FIG. 8 illustrates a data structure of information A#i recorded in theupdate area A of FIG. 7. Referring to FIG. 8, the information A#iincludes information regarding itself and a pointer pointing to alocation of corresponding information B#i recorded in the update area Bof FIG. 7.

FIG. 9 illustrates a structure of the disc 100 of FIG. 1, according toan embodiment of the present invention. For convenience, FIG. 9illustrates the disc 100 as a single record layer disc. Referring toFIG. 9, a lead-in area of the disc 100 includes an access informationarea, a defect management area (DMA), a temporary DMA (TDMA), and arecording condition test area. A lead-out area of the disc 100 includesat least one of an access information area, a DMA, a TDMA, and arecording condition test area. That is, the access information area, theDMA, the TDMA, and the recording condition test area may be present inat least one of the lead-in area and the lead-out area. If the disc 100is a double record layer disc, an access information area, a DMA, aTDMA, and a recording condition test area are included in each of alead-in area and a lead-out area positioned in an inner part of the disc100. Also, an access information area, a DMA, a TDMA, and a recordingcondition test area are included in each of a lead-in area and alead-out area positioned in an outer part of the disc 100.

Here, the TDMA and the recording condition test area correspond to theupdate areas A and B of FIG. 3, 4, or 7. In the access information area,location information regarding temporary management information updatedand recorded in the TDMA, and location information regarding a portionof the recording condition test area where recording conditions are lasttested are recorded. The temporary management information includestemporary defect information and temporary defect managementinformation. The location information regarding a portion of therecording condition test area may specify a start address of a portionof the recording condition test area where recording conditions will betested next time. Alternatively, location information regardinginformation recorded in the TDMA or the recording condition test areamay be selectively recorded in the access information area. In the TDMA,the location information regarding a portion of the recording conditiontest area where recording conditions are last tested is recorded.

In this embodiment, a recording apparatus tests recording conditions inthe recording condition test area for every recording operation, recordsinformation on the disc 100 based on the test result, and recordstemporary management information in the TDMA whenever a recordingoperation ends. Thus, information recorded in the TDMA and informationin the recording condition test area are updated in recording operationunits. Also, location information regarding the recording condition testarea is recorded together with the temporary management information inthe TDMA.

In general, information regarding a structure of a disc on which discdefect management is performed, whether the disc defect management isperformed or not, a location and information regarding a defect, and asize and location of a spare area are recorded in the DMA.

When the disc 100 is loaded into a recording/reading apparatus such asthat shown in FIG. 1, the apparatus generally reads data from a lead-inarea and/or a lead-out area of the disc 100 to determine how to managethe disc 100 and to record data on or read data from the disc 100.However, if the amount of data recorded in the lead-in area and/or thelead-out area increases, a longer time is required for preparing therecording or reproducing of data after the loading of the disc 100. Tosolve this problem or for other reasons, the present invention adoptstemporary defect management information and temporary defect informationthat are to be recorded in a TDMA. The TDMA is allotted to the lead-inarea and/or the lead-out area of a disc, being separated from the DMA.For disc finalization, temporary management information, includingtemporary defect information and temporary defect managementinformation, which is last recorded in the TDMA, is recorded in the DMA.That is, when additional information will not be recorded, that is, discfinalization is required, only last recorded information of thetemporary defect management information and temporary defectinformation, which have been updated several times, are rewritten to theDMA. Thus, the recording/reading apparatus can read defect managementinformation fast from the disc 100 just by reading the last recordeddefect management information, thereby enabling fast initializing of thedisc 100.

In this embodiment, since the disc defect management is performed usinglinear replacement, the temporary defect information includesinformation indicating the position of an area of the disc 100 having adefect and information indicating the position of an area of the disc100 that is replacement for the area having the defect. The temporarydefect management information is used to manage the temporary defectinformation and includes information indicating the position of the disc100 where the temporary defect information is recorded.

In this embodiment, the temporary defect information and temporarydefect management information are recorded every time when a recordingoperation ends. In the TDMA, information regarding a defect, whichoccurs in data recorded during recording operation #1, and informationregarding a replacement area are recorded as temporary defectinformation #1, and information regarding a defect, which occurs in datarecorded during recording operation #2, and information regarding areplacement area are recorded as temporary defect information #2.Further, in the TDMA, management information for managing temporarydefect information #1, #2, . . . is recorded as temporary defectmanagement information #1, #2, . . . The management informationspecifies recording positions of the temporary defect information #1,#2, . . .

When additional data cannot be recorded in the data area or a user doesnot desire to record additional data therein, i.e., disc finalization isrequired, temporary defect information recorded in a temporary defectinformation area and temporary defect management information recorded ina temporary defect management information area are rewritten to the DMA.For disc finalization, the last recorded temporary defect information#1, #2, . . . , #i is read and rewritten to the DMA.

FIG. 10 is a detailed reference diagram illustrating recording of datain a user data area A and a spare area B, according to an embodiment ofthe present invention.

Data can be processed in sector units or clusters. A sector denotes aminimum unit of data that can be managed in a file system of a computeror in an application, and a cluster denotes a minimum unit of data thatcan be physically recorded on a disc at once. In general, one or moresectors constitute a cluster.

There are two types of sectors: a physical sector and a logical sector.The physical sector is an area on a disc where a sector of data is to berecorded. An address for detecting the physical sector is called aphysical sector number (PSN). The logical sector is a unit in which datacan be managed in a file system or an application. An address fordetecting the logical sector is called a logical sector number (LSN). Adisc recording/reading apparatus such as that in FIG. 1 detects therecording position of data on a disc using a PSN. In a computer or anapplication for recording or reproducing data, the entire data ismanaged in units of LSNs and the position of data is detected using anLSN. LSNs and PSNs are mapped by a controller of the recording/readingapparatus, based on whether the disc 100 contains a defect and aninitial recording position of data.

Referring to FIG. 10, A denotes a user data area and B denotes a sparearea in which PSNs are sequentially allocated to a plurality of sectors(not shown). In general, each LSN corresponds to at least one PSN.However, since LSNs are allocated to non-defective areas, includingreplacements recorded in the spare area, the correspondence between thePSNs and the LSNs is not maintained when a disc has a defective area,even if the size of a physical sector is the same as that of a logicalsector.

In the user data area A, user data is recorded either in a continuousrecording mode or a random recording mode. In the continuous recordingmode, user data is recorded sequentially and continuously. In the randomrecording mode, user data is randomly recorded. In the data area A,sections 1 through 7 denote predetermined units of data in which theverify-after-write method is performed.

When the disc 100 is loaded into the recording/reading apparatus, theapparatus tests recording conditions in a recording condition test areaof the disc 100, adjusts a laser power based on the test result, andrecords information on the disc 100. As described above, once recordingconditions are tested in a portion of the recording condition test area,the portion becomes unavailable, and thus, another portion will be usedthe next time for testing the recording conditions.

The recording apparatus records user data in section 1, returns to thestart of section 1, and checks if the user data is appropriatelyrecorded or a defect exists in section 1. If a defect is detected in aportion of section 1, the portion is designated as defect #1. The userdata recorded in defect #1 is also recorded on a portion of the sparearea B. Here, the portion of the spare area B in which data recorded indefect #1 is rewritten is called replacement #1. Next, the recordingapparatus records user data in section 2, returns to the start ofsection 2, and checks whether the data is properly recorded or a defectexists in section 2. If a defect is detected in a portion of section 2,the portion is designated as defect #2. Likewise, replacement #2corresponding to defect #2 is formed in the spare area B. Further,defect #3 and replacement #3 are designated in section 3 of the userdata area A and the spare area B, respectively. In section 4, a defectdoes not occur and a defective area is not designated.

The recording apparatus records information regarding defect #1, #2, and#3 occurring in sections 1 through 4 as temporary defect informationTDFL #1 in a TDMA, when recording operation #1 is expected to end, afterthe recording and verifying of data to section 4, i.e., when a userpresses the eject button of a recording apparatus or recording of userdata allocated in a recording operation is complete. Also, managementinformation for managing temporary defect information TDFL #1 isrecorded as temporary defect management information TDDS #1 in the TDMA.Also, location information regarding a portion of the recordingcondition test area in which a next test will be performed is furtherrecorded in the TDMA.

When the disc 100 is again loaded, recording operation #2 starts,recording conditions are measured in the recording condition test area,and data is recorded on the disc 100 based on the measuring result. Morespecifically, during recording operation #2, data is recorded insections 5 through 7 and defects #4 and #5 and replacements #4 and #5are formed in the user data area A and the spare area B, respectively,as explained for sections 1 through 4. If recording operation #2 isexpected to end, the recording apparatus records information regardingdefects #4 and #5 as temporary defect information TDFL #2. Thereafter,management information for managing the temporary defect informationTDFL #2 is recorded as temporary defect management information TDDS #2in the TDMA. Also, location information regarding a portion of therecording condition test area in which a next test will be performed isfurther recorded in the TDMA. When a predetermined number of recordingoperations are performed as described above, location informationregarding last recorded temporary management information recorded in theTDMA, and location information regarding a portion of the recordingcondition test area where recording conditions will be performed, arerecorded in an access information area of the disc 100. The temporarymanagement information includes temporary defect information and defectmanagement information.

According to the present invention, an access time for the disc 100 canbe reduced as described below.

If ECC is performed in block units and reproduction time of a block is1, data recording is performed in block units that are also ECC units.When data recording is performed in update areas A, B, and C accordingto a recording operation and as a result, the amount of information tobe updated exceeds a block, the access information area is very helpful.When information to be updated can be recorded within a block, a numberof times of performing recording operations is equivalent to a number ofblocks used. In this case, it is easy to estimate a recording positionof information updated.

When information to be updated according to a recording operation can berecorded within a block, the information is updated in a followingupdate area A, B, or C whenever a following number of recordingoperations are performed:

update area A: 1000 blocks, a number of recording operations=a

update area B: 1000 blocks, a number of recording operations=b

update area C: 1000 blocks, a number of recording operations=c

In this case, a time for obtaining desired information from therespective update areas A, B, and C depends on whether the accessinformation is present or not in the disc 100, as follows:

when the access information area is present: (a+b+c)/30+(a+b+c)%30

(% indicates a modular operation)

when the access information area is not present: a+b+c

In conclusion, the time for obtaining desired information from therespective update areas A, B, and C is the same regardless of theinclusion of the access information area, until a recording operation isperformed thirty times, for example. However, once a number of times ofperforming the recording operation is more than 30, a time required toreproduce information from twenty nine blocks can be saved when therecording operation is further performed thirty times. If a recordingoperation is performed 299 times in an update area, it is possible tosave a time required to reproduce information from 260 blocks, i.e.,9*29−1=260. In other words, if the disc 100 does not include the accessinformation area, the time required to reproduce information from 299blocks is spent accessing an update area and scanning and obtaining newinformation from the update area. However, if the disc 100 includes theaccess information area, the time required to reproduce information fromonly 39 blocks is spent. Accordingly, the inclusion of the accessinformation area into the disc 100 causes a reduction in a time forobtaining recent information.

As described above, according to the present invention, it is possibleto minimize an access time for accessing a write-once disc, on whichpredetermined information is updated and recorded at a new position, soas to read the updated information.

Although a few embodiments of the present invention have been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A method of reducing an access time for accessing a write-once discwith at least one record layer, the method comprising: sequentiallyrecording updated predetermined information in at least one update areawhich is present in at least one of a lead-in area, a data area, alead-out area, and an outer area of the disc; and recording locationinformation regarding the updated predetermined information, in anaccess information area present in at least one of the lead-in area, thedata area, the lead-out area, and the outer area.
 2. The method of claim1, wherein the recording of the location information is performedwhenever a predetermined number of recording operations end.
 3. Themethod of claim 1, wherein the recording of the location information isperformed whenever a predetermined number of blocks of the update areaare filled with data.
 4. The method of claim 1, wherein during therecording of the location information, the location information isrecorded in the access information area several times.
 5. A method ofreducing access time of a write-once disc including at least one recordlayer, the method comprising: sequentially recording updatedpredetermined information in a plurality of update areas which arepresent in at least one of a lead-in area, a lead-out area, and an outerarea of the disc; recording location information regarding the updatedpredetermined information, in one of the update areas; and recordinglocation information regarding the updated predetermined information, inan access information area present in at least one of the lead-in area,the lead-out area, and the outer area.
 6. The method of claim 5, whereinthe recording of the location information is performed whenever apredetermined number of recording operations end.
 7. The method of claim5, wherein the recording of the location information is performedwhenever a predetermined number of blocks of the update area are filledwith data.
 8. The method of claim 5, wherein during the recording of thelocation information, the location information is repeatedly recorded inthe access information area several times.
 9. The method of claim 5,wherein the recording of the location information is performed after apredetermined number of recording operations are performed in one of theupdate areas.
 10. The method of claim 5, wherein the recording of thelocation information is performed when a number of times of updating theupdate areas is a predetermined number.
 11. A method of reducing accesstime to information recorded on a write-once disc, the methodcomprising: testing recording conditions in a recording condition testarea for recording operations; recording information on the disc basedon the test result; and recording temporary management information in atemporary defect management area (TDMA) when a recording operation ends,thereby updating in recording operation units the information recordedin the TDMA and the information recorded on the disc based on the testresult.
 12. A computer readable medium encoded with processinginstructions for implementing the method of claim 11 performed by aprocessor.
 13. A computer readable medium encoded with processinginstructions for implementing the method of claim 1 performed by aprocessor.
 14. A computer readable medium encoded with processinginstructions for implementing the method of claim 5 performed by aprocessor.